1. Field of the Invention
The present invention relates to a method of producing an electrostatic latent image developing toner that is used for developing an electrostatic latent image in an electrophotographic device that uses an electrophotographic process, such as a copying machines, printer, or facsimile, and also relates to the toner and an electrostatic latent image developer that uses the toner.
2. Description of the Related Art
Many electrophotographic methods are already known (for example, see Japanese Patent Publication No. Sho 42-23910). Generally, an image is formed via the multiple steps of electrically forming a latent image, using any of a variety of techniques, on the surface of a photoreceptor (latent image holding member) that uses a photoconductive material, developing the formed latent image using a toner, thereby forming a toner image, transferring this toner image, via an intermediate transfer material in some cases, to the surface of a transfer target such as a piece of paper, and fixing the toner by heating, pressure application, heated pressure application, or a solvent vapor method. Any residual toner on the photoreceptor surface is then cleaned as necessary, using any of a variety of methods, and the photoreceptor is then reused for the development of the next toner image.
A typical technique for fixing the toner image that has been transferred to the surface of the transfer target is the heat roller fixing method, wherein the transfer target to which the toner image has been transferred is passed between a pair of either heated rollers or pressure rollers, thereby fixing the image. Furthermore, another similar fixing method, in which either one, or both of the rollers are replaced with belts, is also known. Compared with other fixing methods, these techniques yield a robust image at greater speed, meaning they offer a higher level of energy efficiency, and also generate minimal environmental impact as the result of volatilization of solvents or the like.
The toner image that has been transferred to the surface of the transfer target by the transfer step is fused and fixed to the surface of the transfer target in the fixing step by heating the toner image with a heated fixing member. In this fixing step, it is well known that unless the fixing member is used to heat not only the toner image, but also the transfer target, then the toner image can not be fixed satisfactorily.
In the fixing step described above, during the process of heating and fixing the toner image, at least a portion of each of the multiple of volatile components that exist within the toner particles that form the toner image undergo volatilization. A number of proposals have been made that focus on those components amongst this multiple of volatile components that generate an odor on volatilization.
For example, Japanese Laid-Open Publication No. 2004-54256 discloses an electrostatic latent image developing toner that is produced by first preparing a dispersion of binder resin particles by conducting a polymerization of a polymerizable monomer in a water-based medium, under conditions that include the addition of a thiol compound that functions as a chain transfer agent in a quantity equivalent to 0.05 to 2.0 mol % relative to the total number of mols of the polymerizable monomer, and then salting out and fusing the binder resin particles to form the toner particles, wherein the quantities of volatile substances and polymerizable monomers within the toner particles, which are detected by head space analysis in the period between the peak detection time (a) for n-hexane and the peak detection time (b) for n-hexadecane, are no greater than 350 ppm and no greater than 50 ppm respectively.
However, volatile substances contained within the toner particles not only generate odors during heat fixing, but can also cause damage to the surfaces of the heat rollers, pressure rollers, heat belts, or pressure belts that function as the fixing members within the image formation device.
Once the surface of a heat roller or pressure roller or the like becomes damaged, the release properties of the damaged portion of the heat or pressure roller are altered, meaning the toner image can no longer be satisfactorily heat fixed to the surface of the transfer target. As a result, the image can no longer be reproduced faithfully, and the image quality deteriorates.
Furthermore, there is also a danger that volatile components contained within the toner particles may adhere to the transfer target surface during the transfer process, causing a deterioration in the long-term storage stability of the transfer target following image formation. In other words, because the volatile components that volatilize during transfer can adhere to, and remain bonded to, the transfer target surface, there is a danger that chemical reactions and the like may occur on the transfer target surface during long-term storage, causing a deterioration in the transfer target surface, such as the development of yellowing.